// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_AUDIO_MAC_AUDIO_INPUT_MAC_H_
#define MEDIA_AUDIO_MAC_AUDIO_INPUT_MAC_H_

#include <AudioToolbox/AudioFormat.h>
#include <AudioToolbox/AudioQueue.h>
#include <stdint.h>

#include <memory>

#include "base/cancelable_callback.h"
#include "base/compiler_specific.h"
#include "base/macros.h"
#include "base/time/time.h"
#include "media/audio/audio_io.h"
#include "media/base/audio_parameters.h"

namespace media {

class AudioBus;
class AudioManagerMac;

// Implementation of AudioInputStream for Mac OS X using the audio queue service
// present in OS 10.5 and later. Design reflects PCMQueueOutAudioOutputStream.
class PCMQueueInAudioInputStream : public AudioInputStream {
public:
    // Parameters as per AudioManager::MakeAudioInputStream.
    PCMQueueInAudioInputStream(AudioManagerMac* manager,
        const AudioParameters& params);
    ~PCMQueueInAudioInputStream() override;

    // Implementation of AudioInputStream.
    bool Open() override;
    void Start(AudioInputCallback* callback) override;
    void Stop() override;
    void Close() override;
    double GetMaxVolume() override;
    void SetVolume(double volume) override;
    double GetVolume() override;
    bool SetAutomaticGainControl(bool enabled) override;
    bool GetAutomaticGainControl() override;
    bool IsMuted() override;

private:
    // Issue the OnError to |callback_|;
    void HandleError(OSStatus err);

    // Allocates and prepares the memory that will be used for recording.
    bool SetupBuffers();

    // Sends a buffer to the audio driver for recording.
    OSStatus QueueNextBuffer(AudioQueueBufferRef audio_buffer);

    // Callback from OS, delegates to non-static version below.
    static void HandleInputBufferStatic(
        void* data,
        AudioQueueRef audio_queue,
        AudioQueueBufferRef audio_buffer,
        const AudioTimeStamp* start_time,
        UInt32 num_packets,
        const AudioStreamPacketDescription* desc);

    // Handles callback from OS. Will be called on OS internal thread.
    void HandleInputBuffer(AudioQueueRef audio_queue,
        AudioQueueBufferRef audio_buffer,
        const AudioTimeStamp* start_time,
        UInt32 num_packets,
        const AudioStreamPacketDescription* packet_desc);

    static const int kNumberBuffers = 3;

    // Manager that owns this stream, used for closing down.
    AudioManagerMac* manager_;
    // We use the callback mostly to periodically supply the recorded audio data.
    AudioInputCallback* callback_;
    // Structure that holds the stream format details such as bitrate.
    AudioStreamBasicDescription format_;
    // Handle to the OS audio queue object.
    AudioQueueRef audio_queue_;
    // Size of each of the buffers in |audio_buffers_|
    uint32_t buffer_size_bytes_;
    // True iff Start() has been called successfully.
    bool started_;
    // Used to determine if we need to slow down |callback_| calls.
    base::TimeTicks last_fill_;
    // Used to defer Start() to workaround http://crbug.com/160920.
    base::CancelableClosure deferred_start_cb_;

    std::unique_ptr<media::AudioBus> audio_bus_;

    DISALLOW_COPY_AND_ASSIGN(PCMQueueInAudioInputStream);
};

} // namespace media

#endif // MEDIA_AUDIO_MAC_AUDIO_INPUT_MAC_H_
